Custom Made Demon King

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver. … It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven?? Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls! — Description from novelcodex.org